For a moment, the image of Richard Alley was dark. The chart projected beside him, clearly visible, showed the ice-core record from Lake Vostok, in central East Antarctica, a powerful signature of Earth's climate over the last 400,000 years. Then the overhead lights came on, and Alley, Evan Pugh professor of geosciences at Penn State, appeared in full color on the video screen. Now, however, the chart of data was bleached white.

In the not-far future, supersonic passenger planes will criss-cross the world's oceans with unnerving frequency. Hundreds of flights a day, according to predictions, will shuttle business travelers from, say, Los Angeles to Tokyo and back before bedtime.

Will the sonic booms that accompany those flights pose problems for marine mammals?